No abstract

A temperature‐dependent relay of chirality is based on the inversion of the nitrogen lone pair in cyclic azasugars. Elimination from the conformation preferred at a given temperature leads to a cyclic imine, and in a subsequent nucleophilic attack the stereochemical information is relayed.

[reaction: see text] Representative simple or polyhydroxylated, pyrrolidine (e.g, DRAM) or piperidine (e.g., DNJ) imines not only are potential carbohydrate-processing enzyme inhibitors that may be formed as regioisomeric variants but also are scaffolds that may be rapidly elaborated to diversely functionalized aza-sugars through highly diastereoselective organometallic additions.

Bromobutyl mannopyranosides have been successfully used as both protected and unprotected glycosyl donors both with and without the use of an external activator.Key words: glycosylation, unprotected glycosyl donors, oligosaccharides.